Personal cooling or warming system using closed loop fluid flow

ABSTRACT

A garment for a personal cooling or warming system, the garment comprising a carrier formed in the shape of the garment, and a bladder comprising at least two channel segments, wherein the channel segments have a substantially flat configuration so as to improve thermal efficiency.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

This patent application claims benefit of:

(1) pending prior U.S. Provisional Patent Application Ser. No.60/300,635, filed Jun. 25, 2001 by Paul A. Chambers for PERSONAL COOLINGOR WARMING SYSTEM USING CLOSED LOOP FLUID FLOW;

(2) pending prior U.S. Provisional Patent Application Ser. No.60/300,694, filed Jun. 25, 2001 by Paul A. Chambers for AUTOMATICCONSTANT TEMPERATURE LIQUID SUPPLY FOR CLOSED LOOP PERSONAL COOLING ORWARMING GARMENTS AND SYSTEMS; and

(3) pending prior U.S. Provisional Patent Application Ser. No.60/300,634, filed Jun. 25, 2001 by Paul A. Chambers for PERSONAL COOLINGOR WARMING SYSTEM USING OPEN LOOP AIR FLOW.

The three above-identified patent applications are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to cooling and warming systems in general, andmore particularly to personal cooling and warming systems adapted to beworn by the user.

BACKGROUND OF THE INVENTION

In many circumstances an individual may require cooling or warmingrelative to an ambient environment in order to remain comfortable and,in the case of some extreme environments, in order to maintainperformance and health.

In some situations the individual may be located inside a structure orthe like; in this case, it is generally most efficient to cool or warmthe interior of the structure, e.g., with air conditioning or heaters.This approach is generally convenient in that it allows more than oneindividual to be cooled or heated at the same time, and it allows theindividual to remain in relative comfort regardless of their preciselocation within the structure.

In other situations the individual may be located in an exteriorenvironment; in this case, it is generally not practical to cool or warmthe ambient environment around the individual, particularly if theindividual is moving about to a significant degree. However, where it isvery hot (e.g., the southwestern border of the continental United Statesduring the summer) or very cold (e.g., the northern border of thecontinental United States during the winter), and where the individualmust be outdoors for prolonged periods of time (e.g., Immigration andNaturalization Service officers, other law enforcement officers,military personnel, sportsmen, etc.), it can be imperative that theindividual be provided with a system to provide them with effectivecooling or heating while they are outdoors.

It can also be important to provide a personal cooling or warming systemfor an individual when that individual must be enclosed within animpermeable protective suit, e.g., a chemical weapons protective suit, abio-weapons protective suit, a radioactivity protective suit, etc.

SUMMARY OF THE INVENTION

As a result, a primary object of the present invention is to provide apersonal cooling or warming system which may be worn by the user.

And another object of the present invention is to provide a personalcooling or warming system which is relatively simple and inexpensive tomanufacture, relatively lightweight and comfortable for the user, andthermally efficient.

Still another object of the present invention is to provide a personalcooling or warming system which will remain substantially effectiveregardless of whether the user is standing, sitting or lying down, andregardless of whether the user is wearing heavy packs or harnesses, etc.

Yet another object of the present invention is to provide a personalcooling or warming system which may be worn beneath an impermeableprotective suit.

These and other objects of the present invention are addressed by theprovision and use of a novel garment for a personal cooling or warmingsystem, the garment comprising: a carrier formed in the shape of thegarment; and a bladder comprising at least two channel segments, whereinthe channel segments have a substantially flat configuration.

In another form of the invention, there is provided a garment for apersonal cooling or warming system, the garment comprising a bladdercomprising at least two channel segments, wherein the channel segmentshave a substantially flat configuration.

And in another form of the invention, there is provided a novel personalcooling or warming system, the system comprising: a garment comprising acarrier formed in the shape of the garment; and a bladder comprising atleast two channel segments, wherein the channel segments have asubstantially flat configuration; and a fluid supply and conditioningunit for supplying temperature-conditioned fluid to the channels.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts and further wherein:

FIG. 1 is a schematic view of a personal cooling and/or warming systemformed in accordance with the present invention;

FIG. 2 is a sectional view taken along line 2—2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3—3 of FIG. 1;

FIG. 4 is a schematic view showing one half of a vest garment;

FIG. 5 is a sectional view taken along line 5—5 of FIG. 4;

FIG. 6 is a schematic view showing another form of garment formed inaccordance with the present invention;

FIG. 7 is a schematic view showing still another form of garment formedin accordance with the present invention;

FIG. 8 is a schematic view showing yet another form of garment formed inaccordance with the present invention;

FIG. 9 is a schematic view showing another form of garment formed inaccordance with the present invention;

FIG. 10 is a schematic view showing the bladder construction for thegarment shown in FIG. 9;

FIG. 11 is a sectional view taken along line 11—11 of FIG. 10;

FIG. 12 is a schematic view showing several different garments formed inaccordance with the present invention and being worn simultaneously by auser; and

FIGS. 13 and 14 are schematic views showing how the bladder may beapplied to only selected portions of the garment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The personal cooling or warming system comprises a garment which is wornby an individual so as to provide personal cooling or warming to thatindividual in order to enhance their comfort and performance and, inextreme cases, protect their health. This garment may take the form of acomplete suit, or it may comprise a vest, shirt, pants, shorts, hat,socks, gloves, helmet liner, scarf and/or any other article of clothing.In other words, while the system can be worn as a single, complete“ensemble” garment, it may also be employed as a discrete garmentcomponent, e.g., as a vest alone, or as pants alone, or as a shirtalone, etc., so as to provide the desired level and concentration ofcooling or warming. The garment is preferably worn beneath the normalclothes (e.g., beneath a uniform) of the user, and is preferably worndirectly adjacent to the skin, although it may also be worn without anouter layer of clothing, and/or it may be worn over an inner layer ofclothing, etc.

The garment acts as either a heat sink to rid the body of excess heatbuildup (i.e., for cooling) or as a heat source to prevent excesscooling of the body (i.e., for warming), whereby to provide the userwith a comfortable and healthy working environment. To this end, thegarment includes a bladder which contains a working fluid (e.g., water,glycol mixtures, alcohol, etc.) which is preferably cooled or warmed(e.g., with an ice bath, a refrigerated supply source, a hot or coldthermal gel bath, an electrically heated supply, a thermoelectric heatpump, etc.) as appropriate for the desired function.

More particularly, and looking now at FIG. 1, there is shown a garment 5which is formed in accordance with the present invention. For thepurposes of example but not limitation, the garment 5 shown in FIG. 1 isin the form of a vest, although other types of garments may also beformed. More particularly, the garment shown in FIG. 1 is half of avest, i.e., the left half or the right half, with an armhole H providedin the middle of the structure.

Garment 5 generally comprises a carrier 10 to which is secured a bladder15.

Carrier 10 preferably comprises one or more pieces of fabric or the likewhich is formed in the shape of the garment desired, e.g., in the shapeof the vest shown in FIG. 1, or in the shape of an athletic shirt (alsosometimes referred to as an “A shirt” or “tank top”) such as shown inFIGS. 6–10, or in the shape of shorts such as shown in FIGS. 12–14, etc.Carrier 10 is formed out of a material which is capable of supportingbladder 15 and which provides good thermal transmission to and from theunderlying skin. If desired, carrier 10 may be formed out of a materialsuch as cotton, or a fleece-like material such as Polartec®, or anintegrated, unitary, semi-elastic knitted or woven material, etc. Ifnecessary, carrier 10 may be fitted with various snugging-down and/orclosure devices (e.g., Velcro™ snaps) so as to ensure a close fit withthe body of the user. Carrier 10 may comprise a single layer of material(FIG. 2), to which bladder 15 is secured; alternatively, carrier 10 maycomprise two layers of material (FIG. 3), one on each side of thebladder, with the bladder being secured to one or both layers of fabricso as to form a laminated unitary garment.

Bladder 15 is preferably in the form of a series of interconnected,convoluted channels 20 that provide multiple, redundant flow paths alongat least part, and preferably substantially all, of the garment.Preferably bladder 15 includes an input port 25 (FIG. 1) and an outputport 30 (FIG. 1) by which the working fluid may be introduced into, andwithdrawn from, channels 20. Preferably channels 20 are arranged so asto effect a reasonably even flow throughout the garment. This even flowdistribution may be achieved through the relative sizing of the channels20 and/or through the use of flow diverters (not shown) located at thepoint where a given channel branches into two or more subsequentchannels. This even flow distribution can be important, particularlywith a complex garment such as a vest with differential loading (e.g.,where a heavy load is carried on the back) and/or where several garmentsare worn together.

Each of the flow channels 20 is preferably fabricated as a substantiallyflat tube (FIGS. 2 and 3) between two opposing walls 40, 45. In onepreferred form of the invention, this is achieved by placing tworelatively large sheets 50, 55 in opposing relation to one another andthen bonding them together (e.g., with heat sealing) at selectedlocations so as to form the fluid-tight channels, with subsections ofsheets 50, 55 forming the opposing walls 40, 45. One or both of the tworelatively large sheets 50, 55 may then be mounted to carrier 10depending on whether carrier 10 comprises a single layer of material(FIG. 2) or two layers of material (FIG. 3). If desired, where bladder10 is fabricated out of relatively large sheets of material, some or allof the “unused” sheet material extending between channels 20 maysubsequently be removed, e.g., by die cutting. Removal of such materialmay render bladder 15, and hence garment 5, more flexible.

The bladder's opposing walls 40, 45 are formed out of afluid-impermeable material which is assembled so as to form the fluidcontaining channels 20. In one preferred form of the invention, opposingwalls 40, 45 are formed out of polyurethane. More particularly, in onepreferred form of the invention, bladder 15 is preferably fabricatedfrom two large sheets 50, 55 of polyurethane sheet stock, with thespecific material selection being a function of the intended workingfluid, the system's required pressure, the garment's requiredflexibility, etc., and may be custom tailored to a particularapplication. By way of example but not limitation, bladder 15 may befabricated from 0.009 or 0.015 inch thick natural, ether-based, PT 9200polyurethane sheets of the type produced by Deerfield Urethane of SouthDeerfield, Mass.

A ribbon 60 is preferably disposed in channels 20, between opposingwalls 40, 45. Ribbon 60 is formed out of a material which is relativelyimpervious to the working fluid flowing in channels 20 and relativelyresistant to compressing. The ribbon 60 is preferably attached to bothof the opposing walls 40, 45, whereby to help hold channels 20 in theirdesired flat configuration. Alternatively, however, ribbon 60 may beattached to only one of the opposing walls 40, 45 (e.g., the outer wall40); in this case, the flat configuration of channels 20 may bemaintained by appropriately fashioning opposing walls 40, 45 andsecuring them to carrier 10.

The flat configuration of channels 20 and the presence of ribbon 60therein together provide several important functions:

(1) the flat cross-section of channels 20 maximizes skin contact areafor more efficient heat transfer;

(2) the presence of ribbon 60 in channels 20 reduces the volume of fluidrequired for a given channel diameter and contact area, thereby reducingthe overall fluid volume (and weight) of the system—in other words,inasmuch as the ribbon 60 takes up considerable volume within thechannel 20 (e.g., over 50% in some designs) but does not reduce theeffective area of fluid in contact with the skin, it reduces the volumeof fluid required to fill the garment's bladder while still providingthe desired contact area;

(3) the ribbon 60 minimizes “squeeze-off” of fluid flow caused by, forexample, point pressure from restraint harnesses (e.g., safety belts) orload-carrying harnesses (e.g., SCBA Packs), etc., or from area pressureimposed by the user sitting on or leaning against a firm surface—moreparticularly, since the ribbon 60 is relatively resistant tocompressing, and hence can only be compressed so far, it always providesa degree of physical separation between the two opposing walls 40, 45 ofthe flat channel, and hence always ensures a flow path for fluid to passbetween the sides of the ribbon and the side edges of the channel: andto optimize this performance, the ribbon 60 can have varying degrees ofdensity and stiffness according to their location in the garment (e.g.,in the case of a vest, the ribbon in the upper back region could bestiffer so as to better resist the “squeeze-off” from heavy loads); and

(4) the ribbon 60 can be secured to the inside face of the wall 40 andso effect all of the foregoing functions even while minimizing thesurface area of fluid which is exposed to the ambient conditions on theoutside face of the channels and garment—this minimized exposure of theworking fluid to the environment, plus the insulating properties of theribbon 60, minimizes heat gain/loss to the environment from the workingfluid, thereby maximizing the thermal capacity available forcooling/warming the body of the user.

The ribbon 60 may be fabricated out of any material which is consistentwith one or more of foregoing functions. By way of example but notlimitation, in one preferred form of the invention, ribbon 60 is formedout of a closed cell foam. And in one particularly preferred form of theinvention, ribbon 60 is formed out of 2 pound, 3/16 inch thick, whitevellum closed cell foam material of the type produced by New EnglandFoam of Hartford, Conn.

Input port 25 (FIG. 1) and output port 30 (FIG. 1) may be any fittingswhich are consistent with delivering fluid to, and removing fluid from,bladder 15. In one preferred form of the invention, these fittings areconfigured as simple “female” couplers that can interface to any supplyand return line system through appropriately-sized “barbed” malefittings. By way of example but not limitation, these fittings may beNo. 727 Acur right angle valves of the type produced by Halkey Robertsof St. Petersburg, Fla. These female fittings connect to male quickconnect couplers used to deliver fluid to, and remove fluid from, thesystem, e.g., such as male quick connect couplers of the type availablefrom Colder Products Company, St. Paul, Minn. The garment 5 isconstructed so that input port 25 and output port 30 are exposed foreasy connection to liquid supply and return lines. These fittings may bepositioned anywhere on the garment to protrude from the outer facethereof, or from an edge thereof so as to provide maximum comfort whenworn under a heavier outer garment (e.g., an armored vest). In the casewhere input port 25 and output port 30 are on the same side of thegarment as a layer of carrier 10, the layer of the carrier is recessed(e.g., either by terminating the carrier short of the fittings or byforming holes in the carrier) so as to facilitate easy access to theinport port 25 and the output port 30.

The garment 5 is designed to facilitate large-scale, semi-automatedmanufacturing at minimum cost. To this end, each garment is preferablyfabricated from identical halves that are assembled together in amirrored manner so as to produce the complete garment. Each component ofthe garment (carrier 10, bladder 15 and ribbons 60) are preferably diecut and then assembled on jigs in order to quickly and reliably locatethem in the correct relative positions. The bladder sheets, inlet andoutlet fittings, and foam ribbons are preferably RF welded and/orthermally welded and/or adhesively bonded into a two-ply laminatesub-assembly in a single welding operation; this sub-assembly is thensecured to the carrier with a combination of adhesive and sewn edgetaping. The adhesive is preferably a heat activated adhesive film of thetype produced by Bemis Co. of Shirley, Mass. Alternatively, the bladdersheets, inlet and outlet fittings and foam ribbons are preferablysecured to one another, and the bladder secured to the carrier, in asingle welding or bonding operation. In one preferred form of theinvention, the bladder is preferably secured to the carrier via awelding or other heating process so that the material of the bladderextrudes into the weave or the pores of the carrier so as to effect asecure attachment. Among other things, this construction providesgreater flexibility to the garment.

By way of example but not limitation, the embodiment shown in FIGS. 4and 5 is half of a vest, i.e., the left half or the right half, with thearmhole H formed therein. The closure system preferably comprisesVelcro® hook and loop fastener tape 65 sewn to both sides of the frontof the vest. Elastic panels are then sewn onto the garment as theconnection between the two halves of the vest down the spine joint line.This elastic provides some stretch to the vest and allows it to snugonto the user and to accommodate different user sizes and shapes and tomaintain optimum skin contact.

By way of further example but not limitation, the embodiment shown inFIG. 6 is an athletic shirt formed out of single assembly, with thefront and back sides of the shirt initially in side-by-side relation. Ata subsequent stage of manufacture, the front and back sides are foldedagainst one another and then secured together so as to form the completeshirt. In this situation, and particularly where the carrier materialhas some elasticity to it, the system may not require additional closuresystems.

FIG. 7 shows an athletic shirt which is generally similar to the shirtshown in FIG. 6, except that with the shirt of FIG. 7, fresh fluidentering input port 25 is directed to the two halves of the shirt inparallel, rather than serially as is the case with the shirt of FIG. 6.With the construction of FIG. 7, channel ends A are connected togetherwhen the two halves of the shirt are joined so as to enable proper fluidflow.

FIG. 8 shows another possible athletic shirt construction for applyingfresh fluid to both halves of the shirt in parallel: here, each half ofthe shirt has its own independent network of channels 20, and each halfof the shirt has its own input port 25 and output port 30.

FIGS. 9–11 show still another possible athletic shirt construction.Here, the garment comprises two halves, each with its own unique channelpattern. One of the halves has input port 25 and output port 30. Whenthe two halves of the shirt are joined together so as to form thecomplete garment, channel ends A are connected together and channel endsB are connected together, whereby to enable proper fluid flow.

FIG. 12 illustrates how separate garments 5 (e.g., an athletic shirt andshorts) may be combined for the desired anatomical coverage. In thisrespect it should be noted that each of the garments may receive fluiddirectly from the fluid source (i.e., in parallel to one another); orthe garments may be linked together so that the output of one is fed tothe input of another (i.e., so that the garments are linked in serieswith one another). It should also be appreciated that the garments maybe linked to one another so that one of the garments receives fluid fromthe fluid source and that garment is adapted to supply fluid to, andreceive fluid from, a second garment such that the flow through thatsecond garment is in parallel to the flow through the first garment.

FIGS. 13 and 14 illustrate how channels 20 may be disposed over onlyselected portions of the garment if desired.

Garment 5 is intended to be used as follows.

Temperature controlled fluid (either cooled or warmed relative to theuser's body surface temperature) is pumped to the garment from thesupporting fluid supply and conditioning system via the inletfitting(s). This supporting fluid supply and conditioning system may beany one of the fluid supply and conditioning systems known in the artand consistent with the present invention. The line pressure of thefluid (e.g., 10 gallons per hour at 3–4 psi) is sufficient to distendthe flow channels, thereby providing regions around the enclosed ribbon60 through which the fluid flows. This flowing fluid acts as a heatexchanger with the body of the user through several heat transfermechanisms, including:

(1) direct conduction from the skin into the fluid through the bladderwall (and through any intervening carrier layer which may be present);

(2) convection from the air layer surrounding the body and captured bythe user's clothing; and

(3) evaporative cooling by the wicking action of the sweat through thefabric liner (if the garment includes a carrier layer interposed betweenthe body of the user and the bladder).

The fluid is channeled around and through the garment in a controlledmanner which is achieved through the bladder channel design (e.g., therelative sizing of the channels 20) and/or the incorporation of flowdiverters (not shown) at channel branch points. The flow exits thegarment through the outlet fitting(s). The working fluid returns fromthis point to the conditioning unit to be re-cooled or re-heated asappropriate.

System performance is generally a function of flow rate (typically inthe range of 5–12 gallons per hour), the thermodynamic capacity of theworking fluid, the working fluid-to-body skin temperature differential,the effective heat exchange contact area, the thermal transmissionco-efficients of system materials, etc. In this respect it will beappreciated that only the last two items are characteristics of thegarment system; the remainder of the items are functions of the fluidsupply and conditioning system.

The fluid supply and conditioning system may be any system which canprovide sufficient flow and pressure (e.g., 5–10 gallons per hour, at3–4 psi) of the cooled or warmed fluid (as appropriate) to the garment.This could be a refrigerated reservoir (e.g., chilled by ice, apreviously frozen thermal gel or thermoelectric modules) or heatedsupply (e.g., warmed by a previously heated thermal gel orthermo-electric modules). The conditioned fluid is then driven aroundthe circuit by a small electric pump. The system is preferably fittedwith control valves and flow limiters as necessary so as to providecontrol to the wearer. By way of example but not limitation, liquidconditioning may be accomplished with ice packs, MicroCore® and CoolIce® thermal gel packs, and a Ferrotec™ or MELCOR™ thermoelectricmodule-based heat exchanger. The circulating pump used may be of thetype available from Smart Pumps, Inc., San Jose, Calif.; HargravesTechnology Corp., Mooresville, N.C.; and PAR Technologies, Newport News,Va.

If desired, and depending on the nature of the cooling/warming systemsupplying the garment, a thermostatic switch (thermostat) may beintegrated into or onto the garment to monitor fluid temperature and tosupply input to the control system for the fluid supply and conditioningunit.

Various advantages are achieved through the use of the presentinvention. Among these are:

(1) fluid flow is substantially prevented from being squeezed off bynormal body/seat, body/harness, etc., contact pressure;

(2) flow channels are designed to maintain their flat shape and, aidedby the enclosed ribbons 60, maximize heat exchange contact area andhence efficiency;

(3) flow channels partially filled by the ribbons 60 minimize fluidvolume requirements, thereby minimizing system weight and fluidreservoir volume;

(4) universal inlet and outlet fittings allow maximum interchangeabilitywith existing fluid supply and conditioning systems and provide ease ofinterface to all fluid supply and conditioning systems;

(5) elastic panels and adjustable closures or, more preferably, the useof somewhat elastic, skin-friendly (e.g., natural cotton) carriermaterials maximize the quality of the garment fit and hence system heatexchange efficiency;

(6) the system's laminated configuration allows for simplesemi-automated assembly at minimum cost; and

(7) the streamlined cross-section of the garment and its weldedfabrication maximizes durability and resistance to wear during thenormal laundering process, thereby maximizing garment life.

It should also be appreciated that various modifications may be made tothe embodiments described above without departing from the scope of thepresent invention.

Thus, for example, in the preceding discussion it was indicated thatopposing walls 40, 45 of channels 20 are preferably formed byselectively bonding together two relatively large sheets 50, 55 ofmaterial. However, if desired, opposing walls 40, 45 may be formed bylong strips of material which are bonded together along their parallelouter edges, with one of the walls 40, 45 then being mounted to carrier10.

It is also contemplated that bladder 15 may be formed by two largesheets 50, 55 of material selectively bonded together so as to form thechannels 20; by forming bladder 15 with the proper shape (e.g., in theshape of a vest), it may then be worn as is, without the addition of thecarrier 10.

Still other changes will be obvious to persons skilled in the art inview of the present disclosure.

1. A garment for a personal cooling or warming system, said garmentcomprising: a carrier formed in the shape of the garment; a bladdercomprising at least two channel segments, said channel segments eachhaving a substantially flat configuration; and a ribbon disposed in saidchannels; wherein said ribbon comprises a white vellum closed cell foamand is relatively impervious to fluid flowing in said channels.
 2. Agarment for a personal cooling or warming system, said garmentcomprising: a carrier formed in the shape of the garment; a bladdercomprising at least two channel segments, said channel segments eachhaving a substantially flat configuration; and a ribbon disposed in saidchannels; wherein said ribbon is attached to at least one wall withinsaid channels; and wherein said ribbon comprises a white vellum closedcell foam and is relatively resistant to compressing.
 3. A garment for apersonal cooling or warming system, said garment comprising: a carrierformed in the shape of the garment; a bladder comprising at least twochannel segments, each channel segment having a substantially flatconfiguration; and a ribbon disposed in said channels; wherein saidribbon comprises a white vellum closed cell foam and is impervious tofluid flowing in said channels and is resistant to compressing.
 4. Agarment for a personal cooling or warming system, said garmentcomprising: a carrier formed in the shape of the garment; a bladdercomprising at least two channel segments, each channel segment having asubstantially flat configuration; and a ribbon disposed in saidchannels; wherein said ribbon comprises a white vellum closed cell foam.5. A garment for a personal cooling or warming system, said garmentcomprising: a carrier formed in the shape of the garment; and a bladdercomprising at least two channel segments, wherein said channel segmentshave a substantially flat configuration; wherein a ribbon is disposed insaid channels; wherein said ribbon comprises a closed cell foam; andwherein said ribbon comprises white vellum closed cell foam.
 6. Agarment for a personal cooling or warming system, said garmentcomprising: a carrier formed in the shape of the garment; a bladdercomprising at least two channel segments, each channel segment having asubstantially flat configuration; and a ribbon disposed in saidchannels; wherein said ribbon comprises a white vellum closed cell foamand the composition of said ribbon differs according to a locationthereof on the garment.